There is a withdrawing mechanism, provided with a catcher on a door frame, for catching a striker, provided on a door, in a prescribed position when the door is operated to rotate toward a closed position. Such catcher is provided so as to rotate reciprocally between a standby position and a withdrawn position, and is forcibly rotated by force of a spring from the prescribed position of rotation up to the withdrawn position, thereby to assist the forward movement of the door toward the closed position. (See patent document 1)
Here, in such withdrawing mechanism, the forward movement of the door can be assisted over a wider range as the amount of rotation of the catcher is increased. However, for example, in the case when an apparatus main body supporting the catcher is provided on the door frame of such door, there is a requirement to make the width of the apparatus main body as small as possible because there is a limitation as to the width of the door frame in the direction of forward movement, that is, the front-to-back direction, of the door, and accordingly there is a limitation as to how much the amount of rotation of the catcher can be increased to assist the forward movement of the door over a wider range.
Also, in such withdrawing mechanism, damping force is applied through the catcher to the forward movement of the door by plunging of a piston rod of a piston damper in linkage with the rotation of the catcher. However, it is difficult to ensure a great amount of plunging by only having the piston rod plunged by the rotation of the catcher, and therefore it may be difficult to apply a sufficient damping force to the forward movement of the door.